<p>When you launch Xcode it will ask you what you want to do, and I’d like you to choose “Get Started with a Playground” – this is a sandbox where you can type Swift code and see immediate results.</p>
<p>The default is a blank playground for iOS, which is fine, so click Next then Create to save it on your desktop.</p>
<p>In this video I want to introduce you to variables, which are places where you can store program data. They are called variables because they can <em>vary</em> – you can change their values freely.</p>
<p>Playgrounds start with a line of code that creates a variable for us:</p>
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<p><span class="keyword">var</span> str <span class="operator">=</span> <span class="string">"Hello, playground"</span></p>
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<p>That creates a new variable called <code>str</code>, giving it the value “Hello, playground”. On the right of the playground you can see “Hello, playground” in the output area – that’s Xcode showing us the value was set.</p>
<p>Because <code>str</code> is a variable we can change it:</p>
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<p>str <span class="operator">=</span> <span class="string">"Goodbye"</span></p>
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<p>We don’t need <code>var</code> the second time because the variable has already been created – we’re just changing it.</p>